issue #30: Implement methods new and create of categories controller
issue #30: Implement methods new and create of categories controller

fga-gpp-mds/2017.1-SIGS,fga-gpp-mds/2017.1-SIGS,fga-gpp-mds/2017.1-SIGS,fga-gpp-mds/2017.1-SIGS,fga-gpp-mds/2017.1-SIGS